Despite the ubiquitous use of instructional videos in both formal and informal learning settings, questions remain largely unanswered on how to design and develop video lessons that are often used as the primary method for delivering instruction in online courses. In this study, we experimented with a model of seven principles drawn from instructional design theories for designing and developing video lessons for an online graduate course. Feedback was collected from students through surveys on their perceptions of the effectiveness of the video lessons and the overall course quality for eight semesters. This paper shares the instructors' experience on the design and development of the video lessons as well as the survey findings. Implications of the findings for instructional design and future research are also discussed.